The data from the Mars Express Lander Communication system (MELACOM) that tracked Phoenix was received on Earth soon after the Phoenix landing.
>>>
Listen now
As Mars Express flew over
This animation (Mpeg, 9MB) shows the signal of Phoenix’s descent, recorded by MELACOM.
The spike in the animation, between frequencies of 7 and 8 kiloHertz, shows the transmission from Phoenix itself.
The lander can be seen in the animation starting from about 342 s after the start time and disappears at about 1085 s. This shows Mars Express picking up on the Phoenix signal and tracking it while closing in on the lander; the closest Mars Express got to Phoenix was 1550 km.
As Mars Express flew away, the lander deployed its parachute, separated from it and landed, the signal from the lander was cut off.
The shift of the spike seen in the animation, is due to the so-called Doppler effect, which is very similar to what we hear when listening to the whistle of a passing train.
The signal was tracked successfully, even during the expected transmission blackout window of the descent, until the lander was out of Mars Express’s view. The transmission blackout window is caused because of ionisation around the probe, which builds up as the lander descends through the atmosphere and only very weak signals come through.
The rest of the recording, the start and the end, contains background noise generated by Mars Express itself.
Science observations
During the descent, all of the capabilities of Mars Express were focussed on tracking Phoenix with MELACOM. Unfortunately, the science observations carried out during the descent did not lead to the anticipated results.
Apart from these observations, the Planetary Fourier Spectrometer (PFS) on board Mars Express has been collecting relevant data since 8 May this year in anticipation of the Phoenix landing. This includes information on the physical conditions of the Martian atmosphere (temperature, pressure and density) above the expected the landing site. This data was provided to NASA in support of their observations of the physical conditions in the atmosphere prior to landing.
Over the next few days, Mars Express will monitor Phoenix using MELACOM 15 more times; at least one of these will be used to demonstrate and confirm that the ESA spacecraft can be used as a data relay station for NASA, receiving data from the surface and transmitting test commands to the lander.
Detailed information about the descent and landing will be available once the data from all the fly-overs is processed and analysed over the next few weeks.
Source: European Space Agency
Related stories:
Planets Align for the 4th of July
News Flash: On 4th of July weekend, NASA forecasts lights in the sky. No, not those lights. Look beyond the fireworks. Almost halfway up the western sky, just above the twilight glow of sunset, a trio of worlds is gathering: Saturn, Mars and the crescent Moon.
Mars Sample Return: The next step in exploring the Red Planet
ESA and the Centre National d'Etudes Spatiales (CNES) will be co-hosting, in cooperation with NASA and the International Mars Exploration Working Group (IMEWG), an International Conference on 9 and 10 July in the Auditorium of the Bibliothèque Nationale de France in Paris to discuss the next step in the exploration of Mars.
First images from Phoenix Mars lander
ESA completed a key step in its ongoing support to NASA's Phoenix mission, when signals from the Phoenix Mars lander recorded by Mars Express were successfully received at ESA's Space Operations Centre (ESOC), Darmstadt, Germany. NASA has just made the first few images available.
Phoenix probe lands on Mars (Update 4)
NASA's Phoenix spacecraft landed in the northern polar region of Mars Sunday to begin three months of examining a site chosen for its likelihood of having frozen water within reach of the lander's robotic arm.
Mars Express mission controllers ready for NASA Phoenix landing
ESA's Mars Express mission control team are ready to monitor Phoenix's critical entry, descent and landing onto the Martian surface on 26 May 2008.
Spacecraft at Mars Prepare to Welcome New Kid on the Block
Three Mars spacecraft are adjusting their orbits to be over the right place at the right time to listen to NASA's Phoenix Mars Lander as it enters the Martian atmosphere on May 25.
Mars Express one of three orbiters preparing for Phoenix landing
A trio of NASA and ESA spacecraft orbiting Mars are preparing for the 25 May arrival of NASA's Phoenix lander. ESA's Mars Express has already started adjusting its orbit to provide critical back-up monitoring of Phoenix.
Interplanetary networking: ESA's Mars Express will keep an eye on NASA's Phoenix
ESA’s Mars Express will keep an eye on NASA’s Phoenix lander as it makes its way to the Martian surface, setting an example for international cooperation and interplanetary networking.
